Pipe coupling

Abstract

A coupling for connecting two tubular members. The coupling being comprised of two hubs with annular flanges having axially outwardly facing frustoconical surfaces. The hubs have axially inwardly facing tapered faces, the radially innermost point of said tapered faces being perpendicular to the axis of the tubular members. The tapered faces of the hubs have registering seal rings grooves formed therein, a seal ring being positioned in the seal ring grooves. The hubs are held together by a pair of outer clamps having inner surfaces shaped for engaging the axially outwardly facing frustoconical surfaces of the hubs. Compression of the clamps toward one another forces the inwardly facing tapered surfaces toward one another and brings them into engagement. The engagement of the tapered surfaces forms a primary metal-to-metal seal. The seal ring within the seal ring groove forms a secondary metal-to-metal seal.

What is claimed is: 
     
       1. A coupling assembly for connecting tubular members, comprising:
 a first hub defining a flow path, said first hub having an annular radially outwardly extending first flange, said first flange having an annular axially outwardly facing first frustoconical surface, said first hub having an annular axially inwardly facing first tapered sealing face; 
 a second hub defining a flow path, said second hub having an annular radially outwardly extending second flange, said second flange having an annular axially outwardly facing second frustoconical surface, said second hub having an annular axially inwardly facing second tapered sealing face; 
 a first seal ring groove formed in said first tapered sealing face; 
 a second seal ring groove formed in said second tapered sealing face; 
 said first and second seal ring grooves being in register; 
 a seal ring disposed within said first and second seal ring grooves, said seal ring being isolated from said flow path; 
 a clamping assembly comprising a pair of clamps, each of said clamps having an inner surface shaped to engage said first and second frustoconical surfaces of said first and second hubs; 
 a compression assembly operative to force said clamps into engagement with said first and second frustoconical surfaces, said engagement with said first and second frustoconical surfaces forcing said first and second tapered sealing faces into metal-to-metal sealing engagement with one another to form a primary metal-to-metal seal. 
 
     
     
       2. The coupling assembly of  claim 1 , wherein said seal ring has an interference fit with said seal ring grooves. 
     
     
       3. The coupling assembly of  claim 1 , wherein a radially innermost portion of said tapered first sealing face comprises a first seat, said first seat being perpendicular to said flow path, and wherein a radially innermost portion of said tapered second sealing face comprises a second seat, said second seat being perpendicular to said flow path. 
     
     
       4. The coupling assembly of  claim 1 , wherein the compression assembly comprises a plurality of nuts and bolts. 
     
     
       5. The coupling assembly of  claim 1 , wherein said first and second tapered sealing faces are at an angle of from about 0.10° to about 0.30°.